I'm in a similar situation. I've been asked to teach a grappling class to a group of my former TKD team mates at an upcoming summer camp.

I first approached my coach (who started me and awarded me my blue in Japanese Jiu Jitsu) and my corner man who is a purple belt in BJJ and who I train with. With both of their input I have decided to teach a 'submission wrestling' class.

I have 4-5 years of Jiu Jitsu experience and a number of MMA fights and I still went looking for permission. Did I have to? Not really, but I don't even want to misrepresent myself to a group of people who are looking for instruction. When you misrepresent yourself you commit 'Crappling' and you become a 'McSeafood'.

Thanks a bunch for all your answers, I agree totally with the not doing it bit. I'll definitely ask my instructor if he is able to give them a seminar and leave it at that :)

This is the best option.
I don't think Marcello would be happy to "hear" that one of his white belt is showing BJJ techniques without asking him first.
Most people do not understand the problem: that your performance will reflect on Marcello i.e Gracie Barra Sydney.

What Devil said, I've shown for example a boxer friend of mine BJJ/Judo moves because he is fairly familiar with MMA and wanted to know how specific things worked (i.e. arm bar variations). Keep in mind showing someone how a specific move they are curious about works or holding them in side control while they attempt to get out and you point out some things that might help is one thing. Here you a) know the person, b) can explain to him just how little you know and c) cover a specific point. In same same way if my friend showed me the basics of bobbing and weaving I wouldn't tell people I am a trained boxer.

Alternatively, this would be an instructional setting no matter how you spin it. You can clarify all you want but if on a regular basis an instructor who takes money from these people for MA classes and has some authority to promote, regulate, is bringing you in to teach them grappling they will see it as their being trained in grappling to some degree. Regardless of the point about diminishing the reputation of your BJJ instructor, these people will think they have some sort of grappling ability if they are getting taught on a daily basis. Hell, people who wrestle in their backyard on a daily basis think they can wrestle and the point I am trying to make is you are in no way qualified for this.

When I first read the post I thought it might be good b/c they would get their ass kicked in grappling and might seek out actual instruction but first off, few will, and secondly that is not what I think the instructor is recruiting you for. Kicking your friends ass on the ground so he would join up at your gym is one thing, this is a different animal.

There's a very big difference between demonstrating something to a friend or two in an informal setting, and walking into a commercial school or organized club, and running a seminar or class when you are not qualified to do so. Everyone who has been training any amount of time has had friends ask them for a demonstration. There's nothing wrong with doing this. But representing yourself as an instructor is something entirely different.

Even if you are clear that you are no expert, but run a seminar at another club, how might your instructor take that? Especially if he knew nothing about the situation, but then later hears that you are teaching at another club? It can look really bad to your instructor, even if the situation was really simple and harmless, with you just pinning a bunch of noobs and helping them to escape.

I help to run a FMA club, but also train in grappling under a very talented instructor at another club. As I was teaching stickfighting, the grappling issue came up, and I commented on the subject and did a very brief and simple demonstration but would not address the issue thoroughly until I ran it by by my grappling instructor.

He was very appreciative that I did this, and afterwards came down to my stickfighting club and ran a little seminar for free, telling us that if we'd like to pursue it further, I could coach them along for basics that we worked on and refer my stickfighters back to him for anything more advanced. This was a very fair way to do things, imo. My stickfighters definitely need some kind of basic understanding of takedowns, sprawls, and positional work on the ground. Some of them have no further interest in the subject than this, but others have expressed an interest in dropping by the grappling club to get some more in-depth training. It ended up as a win-win for everyone.

Run the situation by your instructor.

Edit: Sorry, didn't realize this was a pretty bad necro that I was responding to.